RECENT ARTICLES

Is there are sweet spot where artificial intelligence systems could have the maximum amount of consciousness while retaining powerful quantum properties?

To build the ultimate artificial mimics of real life systems, we may need to use quantum memory.

A radical interpretation of physics makes quantum theory more personal.

Carlo Rovelli describes how black holes may transition to "white holes," according to loop quantum gravity, a radical rewrite of fundamental physics.

Could giant sea swells help explain how the macroscopic world emerges from the quantum microworld? (Image credit: MIT News)

FQXI ARTICLE

April 29, 2017

The Myth of Gravity

A new model in which gravity is not a fundamental force could—counterintuitively—give a controversial quantum gravity theory a boost. It may also change our picture of spacetime, and do away with dark energy.

April 24, 2010

Erik Verlinde

University of Amsterdam

Gravity may be the force that we are most familiar with in everyday life, but physicists do not yet understand its origin. Newton told us that apples fall towards Earth with an acceleration that depends on the Earth’s mass, the apple’s mass, and its distance from the centre of the Earth, while Einstein described gravity by the warping of the fabric of spacetime. But while these theories describe how gravity works, they don’t explain how it arises.

Verlinde, a string theorist at the University of Amsterdam in the Netherlands, believes that the key to understanding gravity is "information." He was inspired by early work on information storage in black holes by Stephen Hawking and Nobel laureate Gerard ’t Hooft. "When I was about fifteen I saw them on television talking about the physics of elementary particles and black holes," says Verlinde. "I knew then that I wanted to work in that area."

The Television Event Horizon

Hawking and ’t Hooft had both worked on the so-called

Entropic force?

Imagining a particle near a spherical holographic screen

allows you to derive Newton’s law of gravity.

It might sound like re-inventing the wheel, but the approach implies that gravity is nothing more than the result of a system maximising its entropy, or disorder. At first glance, this looks like bad news for the quantum gravity crowd. If gravity is an "entropic force," there is no longer a need for physicists to attempt to reconcile general relativity with quantum mechanics, or hunt for the hypothetical

Quantum Threads

However, not all gravity researchers take that view. Smolin, a long term proponent of loop quantum gravity (LQG), believes that Verlinde’s work is not only compatible with LQG, it could even help to explain how familiar Newtonian gravity might emerge in this picture. According to LQG, spacetime isn’t the smooth fabric that Einstein envisioned; rather, if you zoom down to scales of 10

Smolin notes that Verlinde’s model is tied to earlier work by FQXi member Ted Jacobson, who had shown in 1995 that Einstein’s equations of general relativity could be derived using thermodynamics and the holographic principle. "The wonderful thing about the arguments of Jacobson and Verlinde is they give a deep reason for why a quantum theory of gravity should yield the phenomena of gravitation," Smolin writes in his recent paper (arXiv:1001.3668v2).

There isn’t a fundamental

gravitational interaction.

Is that crazy enough?

gravitational interaction.

Is that crazy enough?

- Paul Frampton

If such derivations of dark energy stand up then Verlinde’s ideas "could in some sense complete general relativity," says physicist Sabine Hossenfelder at the Nordic Institute of Theoretical Physics in Sweden. However, there is still a long way to go before physicists will abandon the notion that gravity is a real force as there are several things that remain vague in Verlinde’s formulation, she adds.

Frampton, however, is convinced that Verlinde is on the right track. "I believe that gravity is entirely explained by increases in entropy; there isn’t a fundamental gravitational interaction," he says. "That’s the bottom line. Is that crazy enough?"

Comment on this Article

Please read the important Introduction that governs your participation in this community. Inappropriate language will not be tolerated and posts containing such language will be deleted. Otherwise, this is a free speech Forum and all are welcome!

function ValidatePostText_main () {
form = document.addPostForm_main;
if (form.postText_main.value == '') {
alert ("The post contains no text");
return false;
}
else {
return true;
}
}

**Your name:**
(optional)

**Important:** In order to combat spam, please select the letter in this menu between 'L' and 'N':
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Recent Comments

read all article comments

Please read the important Introduction that governs your participation in this community. Inappropriate language will not be tolerated and posts containing such language will be deleted. Otherwise, this is a free speech Forum and all are welcome!

Please enter the text of your post, then click the "Submit New Post" button below. You may also optionally add file attachments below before submitting your edits.

HTML tags are not permitted in posts, and will automatically be stripped out. Links to other web sites are permitted. For instructions on how to add links, please read the link help page.

You may use superscript (10

^{100}) and subscript (A_{2}) using [sup]...[/sup] and [sub]...[/sub] tags.You may use bold (

**important**) and italics (*emphasize*) using [b]...[/b] and [i]...[/i] tags.You may also include LateX equations into your post.

Insert LaTeX Equation
[hide]

LaTeX equations may be displayed in FQXi Forum posts by including them within [equation]...[/equation] tags. You may type your equation directly into your post, or use the LaTeX Equation Preview feature below to see how your equation will render (this is recommended).

For more help on LaTeX, please see the LaTeX Project Home Page.

LaTeX Equation Preview

preview equation

clear equation

insert equation into post at cursor

LaTeX equations may be displayed in FQXi Forum posts by including them within [equation]...[/equation] tags. You may type your equation directly into your post, or use the LaTeX Equation Preview feature below to see how your equation will render (this is recommended).

For more help on LaTeX, please see the LaTeX Project Home Page.

LaTeX Equation Preview

preview equation

clear equation

insert equation into post at cursor

Attachments
[hide]

You may optionally attach up to two documents to your post. To add an attachment, use the following feature to browse your computer and select the file to attach. The maximum file size for attachments is 1MB.

Once you're done adding file attachments, click the "Submit New Post" button to add your post.

You may optionally attach up to two documents to your post. To add an attachment, use the following feature to browse your computer and select the file to attach. The maximum file size for attachments is 1MB.

Once you're done adding file attachments, click the "Submit New Post" button to add your post.

QUANTUM ANTIGRAVITY wrote on April 21, 2017

EXPERIMENTAL quantum Anti-gravity — https://quantumantigravity.wordpress.com

I have made a theoretical as well as an empirical scientific discovery

of quantum gravity and quantum antigravity.

Present day quantum gravity theories suffer from

too many mathematical space dimensions, and from

too few conclusive experimental results.

My hypothesis is simple, clear,

and subject to easy empirical verification :...

EXPERIMENTAL quantum Anti-gravity — https://quantumantigravity.wordpress.com

I have made a theoretical as well as an empirical scientific discovery

of quantum gravity and quantum antigravity.

Present day quantum gravity theories suffer from

too many mathematical space dimensions, and from

too few conclusive experimental results.

My hypothesis is simple, clear,

and subject to easy empirical verification :...

ANONYMOUS wrote on June 1, 2016

How does the objects interact? What decides whether to attract or repel each other?

How does the objects interact? What decides whether to attract or repel each other?

ANONYMOUS wrote on April 21, 2016

Does this mean that if a large hollow body was placed in space it's"gravity" for lack of understanding, could be equal to that of say..... Earth? Random virtual particles pressing onto the surface from all regions of space? "Gravity" being equal on the inside of the sphere to"gravity" on the outside perhaps? I'm struggling with practical application of this theory, though tantalizing to the imagination.

Does this mean that if a large hollow body was placed in space it's"gravity" for lack of understanding, could be equal to that of say..... Earth? Random virtual particles pressing onto the surface from all regions of space? "Gravity" being equal on the inside of the sphere to"gravity" on the outside perhaps? I'm struggling with practical application of this theory, though tantalizing to the imagination.

read all article comments